Saving Collector settings always results in settings sync

## Expected Behavior
Changes that do not affect the collectors themselves (e.g. offline thresholds) should not cause a settings resync for all collectors.
If the ingest endpoint is unchanged, we should not force a sync on the entire fleet.

## Current Behavior
Changing the offline threshold causes a config resync.

## Possible Solution
Detect which attributes have changed and have an allowlist for changes that don't require collector sync.

## Steps to Reproduce (for bugs)

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## Context

## Your Environment

* Graylog Version:
* Java Version:
* OpenSearch Version:
* MongoDB Version:
* Operating System:
* Browser version:

## Checklist
[] This issue fix need to be backported.
[] Does this issue have **security** implications?

No files or tests are named. Start by tracing where Collector settings are saved and where that save triggers a fleet-wide config resync; identify which changed attributes determine whether the ingest endpoint or collector configuration is affected. Done means changing offline thresholds no longer resyncs collectors, while changes that require new collector settings still do.

Written by the indexing model from the issue text.